Stump cutting tooth assembly

ABSTRACT

A stump cutting assembly mounted to a stump cutting wheel. Stump cutting assembly is a stump cutting tooth interconnected to the wheel by a holder or block that is fixed to wheel by welding or other equivalent process, an optional debris deflector and a fastener that interconnects tooth and deflector to holder. As wheel rotates about its axis of rotation, the tooth cuts away at wood or other debris in which it comes into contact through the side to side and/or longitudinal movement of a stump grinder unit.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 11/927,040, filed Oct. 29, 2007, now allowed and which, in turn,claims priority to U.S. Provisional Application No. 60/863,225, filedOct. 27, 2006, the both of which are hereby incorporated in theirentireties.

BACKGROUND OF THE INVENTION

The present invention relates generally to stump grinding teeth, andmore particularly to an assembly that facilitates the mounting of astump grinding tooth to a grinding wheel.

Stump grinders are well known in the art. Typically, the grindercomprises a wheel mounted by an axle to a motor. A plurality of cuttingteeth are affixed about the periphery of the wheel, and include cuttingtips, typically composed of carbide or similarly hard substances, brazedthereon. While rotating at high speeds, the wheel is traversed in asideways motion relative to a tree stump with the teeth cutting into andgrinding the stump. Continuously moving the wheel across the stumpresults in the teeth generally grinding the stump into chips.

While the wood generally degrades the edge of the cutting bits,oftentimes they come into contact with foreign objects embedded in thewood, such as rock, nails, or other hard substances. The impact withthese objects accelerates the degradation of the cutting bits. Once theedge is worn beyond an acceptable limit, the tooth or teeth must bechanged.

Traditionally, changing the teeth required the operator to use a drillor other tool to remove bolts that fasten a pocket to the wheel. Theteeth, in turn, are clamped to the wheel by the pockets. This process islaborious, and with conventional teeth, the entire tooth has to bediscarded and replaced with a new tooth. Thus, in addition, to thedowntime associated with changing the teeth, the teeth themselves raisethe expense associated with the grinding operation.

It is therefore a principal object and advantage of the presentinvention to provide a tooth assembly that reduces the labor associatedwith having to change a tooth on a grinding machine.

It is another object and advantage of the present invention to provide atooth assembly that permits cutting bits to be replaced as opposed tohaving to replace an entire tooth, thereby lowering the cost to thelowest consumable.

Other objects and advantages of the present invention will in part beobvious, and in part appear hereinafter.

SUMMARY OF THE INVENTION

In accordance with the foregoing objects and advantages, the presentinvention provides a stump grinding assembly comprises of a wheel andperipherally mounted tooth assemblies. Tooth assemblies compriseindividual grinding teeth held in place by a variety of connectingelements that provide for easy replacement of teeth.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be more fully understood and appreciated byreading the following Detailed Description in conjunction with theaccompanying drawings, in which:

FIG. 1 is a side view of a wheel assembly according to the presentinvention.

FIG. 2 is a tooth assembly according to the present invention.

FIG. 3 is a side view of a wheel assembly according to the presentinvention.

FIG. 4 is an embodiment of a tooth assembly according to the presentinvention.

FIG. 5A-5D is embodiment of a tooth assembly according to the presentinvention.

FIG. 6A-6D is an embodiment of a tooth assembly according to the presentinvention.

FIG. 7A-7D is an embodiment of a tooth assembly according to the presentinvention.

FIG. 8 is an embodiment of a tooth assembly according to the presentinvention.

FIG. 9A-9D is an embodiment of a tooth assembly according to the presentinvention.

FIG. 10 is an embodiment of a tooth assembly according to the presentinvention.

FIG. 11 is a perspective view of an embodiment of a wheel and toothassembly according to the present invention.

FIG. 12A-12C is a cross-section of an embodiment of a tooth assemblyaccording to the present invention.

FIG. 13A-13B is a cross-section of an embodiment of a tooth assemblyaccording to the present invention.

FIG. 14A-C is a perspective view of an embodiment of a tooth assemblyaccording to the present invention.

FIG. 15 is an embodiment of a tooth assembly according to the presentinvention.

FIG. 16A-16D is an embodiment of a tooth assembly according to thepresent invention.

FIG. 17A-17E is an embodiment of a tooth assembly according to thepresent invention.

FIG. 18 is a side view of an embodiment of a wheel assembly according tothe present invention.

FIG. 19 is a perspective view of an embodiment of a tooth assemblyaccording to the present invention.

FIG. 20 is an embodiment of a wheel for a tooth assembly according tothe present invention.

FIG. 21A-21B is an embodiment of a wheel for a tooth assembly accordingto the present invention.

FIG. 22 is an embodiment of a tooth assembly according to the presentinvention.

FIG. 23 is an embodiment of a tooth assembly according to the presentinvention.

FIG. 24 is an embodiment of a tooth assembly according to the presentinvention.

FIG. 25 is an embodiment of a shock absorbing system for a stumpgrinding apparatus.

FIG. 26 is another embodiment of a shock absorbing system for a stumpgrinding apparatus.

DETAILED DESCRIPTION

Referring now to the drawings wherein like reference numerals refer tolike parts throughout, there is seen in FIGS. 1-3 a stump cuttingassembly, designated generally by reference numeral 10, mounted to astump cutting wheel 12. Stump cutting assembly 10 generally comprises astump cutting tooth 14 interconnected to wheel 12 by a holder/block 16that is fixed to wheel 12 by welding or other equivalent process, anoptional debris deflector 18 and a fastener 20 that interconnects tooth14 and deflector 18 to holder 16. As wheel 12 rotates in the directionindicated by arrow D about its axis of rotation R-R, tooth 14 cuts awayat wood or other debris in which it comes into contact through the sideto side and/or longitudinal movement of a stump grinder unit (grindingunit not shown).

With reference to FIGS. 4-7, tooth 14 comprises a body 22 that includesan upper surface 24, a lower surface 26, opposed side surfaces 28, 30,and a front surface 32. In its preferred form, tooth 12 includes cuttingbits 34, 36, preferably composed of carbide, or a similarly hardmaterial, brazened, or otherwise integrated, to shoulders 38, 40,respectively, formed at the interfaces of front surface 32 and sidesurfaces 28, 30, respectively, and at the boundary of lower surface 26.An opening 42 is formed through tooth 14 extending from its lowersurface 26 up through its upper surface 24, for purposes of permittingpassage of fastener 20 therethrough, as will be described in greaterdetail hereinafter. As seen in FIGS. 6A-D, tooth 14 may be comprise twoelements supported by fastener 20 passing therethough.

For purposes of fastening tooth 14 and deflector 18 to holder 16, holder16 and deflector 18 also include openings 44, 46, respectively formedtherethrough. Tooth 14, holder 16, and deflector 18 are assembled withopenings 42, 44, 46, respectively, axially aligned, and fastener 20 thenpassing through opening 44 first, followed by openings 42 and 46, asseen in FIGS. 7A-C. Fastener 20 may be secured via a threaded connectionor other conventional fastening systems. Therefore, if a stump grinderhaving assembly 10 is being used and a tooth 14 needs to be replaced,all that is necessary is for the operator to remove the fastener 20associated with the impaired tooth 14, position a new tooth 20 inposition, and re-fasten the assembly 10 with fastener 20.

In a second embodiment of the present invention shown in FIGS. 8 and9A-D, a tooth 100 includes a post 102 extending outwardly from its uppersurface 104. Post 102, which includes an annular groove 106 formedtherein adjacent its free end and a sealing member 108, such as an0-ring, that is positioned in groove 106, is adapted to be inserted intoopening 44′ formed in holder 16′. A fastening element (not shown) isinserted through opening 44′ and frictionally engages sealing member 108in annular groove 106 to secure the interconnection between tooth 100and holder 16′. To disassemble, an operator need only apply a pullingforce to the end of the fastening member such that it disengages fromannular groove 106.

In a third embodiment shown in FIG. 10, a tooth 200 is equipped with amale dovetail joint 202 formed on its upper surface 204 that interfaceswith a corresponding female portion 210 formed in the lower surface ofholder 16′. An opening formed in dovetail 202 is adapted to receive athreaded fastener 206, which can, for example, be in the form of aPhillips Head screw and that includes a retaining member 208 thatsecurely engages the peripheral edge of wheel 12 and includes an angledextension that includes an opening through which fastener 206 passes andis positioned between the head of fastener 206 and holder 16″.

In a fourth embodiment shown in FIG. 11, a tooth 300 attaches directlyto a wheel 12′ without a holder, but is nonetheless a quick-connect typeof connection. In this embodiment, tooth 300 includes a body region witha first hole 302 formed therethrough and a second opening 304 (theopening 304 may be either open through the periphery of the tooth, asshown, or it may be a hole that is formed through the body region and isnot open through the periphery of the tooth). A post 306 extendsoutwardly from opposing sides of wheel 12′ (actually a pair of posts,one from each side, extend along a common axis), and a slot 308 isformed through wheel 12′ a predetermined lateral distance from post 306.An axle 310 with opposed threaded ends, extends along an axis that istransverse to the plane of the wheel and through slot 308, and includesa medial body portion 312 that is shaped to snugly fit within andconform to the shape of slot 308. In addition, a shock absorbing member314 is also positioned in the space within slot 308 and fills the spacewithin the slot that is not occupied by body portion 312. Shockabsorbing member 314 can be, for example, compressed wire mesh.

In attaching tooth 300 to wheel 12′, opening 302 is passed about post306, and opening 304 is passed over one end of axle 310 (thus thepredetermined lateral spacing between post 306 and axle 310 is equal tothe distance separating openings 302 and 304.) A washer 316 and O-ring318 are then slipped over the end of axle 310, and a nut 320 is threadedonto the end of axle 310 to secure tooth 300 is position relative towheel 12′. To change tooth 300, the operator needs only remove nut 320using a wrench or pliers, pull the damaged tooth off of axle 310, placea new tooth in its place, and re-assemble washer 316, O-ring 318 and nut320.

In a fifth embodiment shown in FIGS. 12-14, a tooth 400 includes anelongated post 402 (with respect to the second embodiment of the presentinvention shown in FIGS. 8 and 9A-D) that extends outwardly from itsupper surface 404. Post 402 is dimensioned to extend entirely throughholder/block 416, which includes an opening 406 formed therethrough foraccepting post 402. Post 402 generally comprises a first portion 408having a first diameter extending from tooth 400, a second portion 410extending from first portion 408 and having a second diameter that isslightly smaller than the first diameter, and an end cap 412 at theterminal end of post 402. The diameter of first portion 408 is selectedto allow frictional engagement with the interior surface of opening 406formed through holder 416. As the diameter of second portion 410 isslightly smaller that first portion 408, post 402 is, at first, easilyreceived within hole 418 and then, as post 402 is advanced further intoopening 406, brought into frictional engagement with holder 416. Tooth400 may be removed from holder 416 by applying an external force to endcap 412, thereby driving post 402 out of opening 406 until first portion408 is no longer in frictional engagement with opening 406. Secondportion 410 may include a circumferential groove 414 formed therein forhousing a sealing member 418, such as an o-ring, for further frictionalengagement with the interior of opening 406.

In a sixth embodiment shown in FIGS. 15-16, a tooth 500 and holder 502are connected to a wheel 504 via a forwardly facing fastener 506 thatextends through an opening 508 formed through tooth 500 to engage holder502, thereby locking tooth 500 in place. Wheel 504 preferably includes aslot 510 formed in a peripheral portion thereof by an arm 512 thataccepts and protects fastener 506 during operation of wheel 504.

In a seventh embodiment shown in FIG. 17-19, a tooth 600 including adovetailed rear surface 602 is interlocked with a correspondinglydovetailed holder 604. Holder 604 abuts against a shoulder 606 formed inthe peripheral edge of wheel 610 and is further held in place by abracket 612. Bracket 612 including an outwardly extending flange 614,through which a pin 616 may pass for engagement with a spring assembly618 positioned within holder 614. Spring assembly 618 includes a post620 having a forward end 622 for engaging a corresponding detent 624formed in tooth 600.

In an eighth embodiment shown in FIGS. 20-21, wheel 700 includes acentrally mounted isolator 702. Isolator 702 comprises a central disc704 maintained between two opposing plates 706, 708. Disc 704 ispreferably formed from a resilient material. Opposing plates 706, 708are interconnected to grinding elements 710. As a result, vibrationscaused by striking hard surfaces, such as rocks, will be transmitted toisolator and absorbed by disc 704.

In an ninth embodiment shown in FIGS. 22-24, a tooth assembly 800comprising a tooth body 802, a deflector 804, and a holder 806. Toothbody 802 is symmetrical about transverse central, longitudinal plane andcomprises opposed front and rear faces 808, 810 and sides 812, 814 towhich cutting bits 816, 818 are secured, respectively. The front andrear faces 808, 810 are each recessed from the terminal ends of cuttingbits 816, 818 and each taper inwardly from their lower edges to theirupper edges.

Deflector 804 and holder 806 are adapted for positing below and abovetooth body 802, respectively. The bottom surface 820 of deflector 804includes a U-shaped channel 822 formed transversely there through for areason that will be described hereinafter.

A series of co-axially, oval shaped openings 824 are formed throughtooth body 802, deflector 804 and holder 806. T-shaped bolt 824 includesan elongated shaft 828 adapted to extend through an be pivotally movablewithin opening 824, and a cylindrical base member 830 that is adapted tobe sealed within U-shaped groove 822. The upper end of shaft 828 isadapted to engage a stump grinding wheel to secure tooth assembly 800 tothe wheel.

It should be noted that alternatives to a U-shaped groove 822 andcylindrical base 830 could be employed so long as the functionality ofpivotal movement and securing shaft 828 are achieved. For instance, ahemi-spherical nut that sits in a correspondingly shaped, hemisphericalindentation formed in the bottom of deflector 804 could be employed.

Due to the symmetry of tooth body 802 and the pivotal movement of shaft828 within opening 824, if the cutting bits 816, 818 wear out, the toothbody 802 can be reversed to permit the opposite, non-worn edges ofcutting bits 816, 818 to be used.

With reference to FIGS. 25 and 26, alternate shock absorbing systems areshown. In FIG. 25, an elastomeric block 900 is mounted to wheel 902 andwill be positioned between the wheel and the rear surface 904 of stumpcutting tooth assembly 906. As an alternate to the elastomeric block900, a compressed wire mesh block could be employed, as could ahydraulic, nitrogen, or other conventional piston and cylinder shockabsorbing member (not shown). Furthermore, with reference to FIG. 26, aleaf spring 910 could be mounted to and between wheel 902 and toothassembly 906. In addition, an electro-mechanical assembly comprising aforce sensor and electronically controlled shock member could beemployed in place of the mechanical absorbing members. In practice, astooth assembly 906 rotates and its tooth impacts a stump, the forcetranslated to the tooth will translate to rear surface 904 which in turnwill be absorbed by shock absorbing member (e.g., elastomeric block,wire mesh block, leaf spring, etc.) 900.

With reference to FIG. 25, tooth assembly 906 could be mounted directlyto shock absorbing member 900, in which case the shock absorber willabsorb forces in multiple dimensions, whereas tooth assembly 906 couldbe mounted to wheel 902 via a hinge pin 912, in which case shockabsorbing member 900 absorbs shock only in one dimension.

What is claimed is:
 1. A stump cutter wheel with a shock absorbingsystem for a stump cutting tooth mounted thereon, comprising: a stumpcutter wheel including an outside perimeter surface; a stump cuttingtooth assembly body mounted to the stump cutter wheel and having a rearsurface; and a shock absorbing member attached to the stump cuttingwheel, wherein a portion of the shock absorbing member extends radiallybeyond the outside perimeter surface of the stump cutter wheel at apoint where the shock absorbing member is attached to the stump cuttingwheel, and is positioned between and in contacting relation to both thestump cutting wheel and said rear surface of said stump cutting toothassembly body.
 2. The stump cutter wheel according to claim 1, whereinsaid shock absorbing member comprises a leaf spring member.
 3. The stumpcutter wheel according to claim 1, wherein said shock absorbing membercomprises an elastomeric block of material.
 4. The stump cutter wheelaccording to claim 1, wherein said shock absorbing member comprises acompressed wire mesh block of material.